Deivifg gear foe bicycles



(No Model.) 2- Sheets-Sheet 1. J. BAU.

` DRIVING GEAR FOR BIGYGLES.

Patented 055. 22, 1595.

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(No Model.) l 2 Sheets- Sheet 2.

Jl R-A..[]':'l DRIVING' GBR FR BIYGLES.

No. 548,592. Patented Oct. 22, 1895.

UNITED STATES PATENT OFFICE.

JOI-IN RAU, OF CHICAGO, ILLINOIS, ASSIGNOR TO FRANK L. SALISBURY, OF SAME PLACE.

DRIVING-GEAR Foe elcYcLEs.

SPECIFICATION forming part of Letters Patent No. 548,592, dated October 22, 1895.

Application tiled April 10, 1895. Serial No. 545,214. (No model.)

.To a'ZZ whom it may concern:

Be it known that I, JOHN BAU, a citizen of the United States, residing at Chicago, in the county of Cook and State ot' Illinois, have invented certain new and useful Improvements in Driving-Gear for Bicycles; and I do hereby declare the following to be a full, clear, and exact description of the invention,whch will enable others Skilled in the art to which it ro appertains to make and use the same.

My invention relates to a new and useful improvement in driving-gear for bicycles.

The objects of my invention are to provide and produce a driving-gear which can be ap- I 5 plied to any safety-bicycle without materially altering the saine, and by means of which the power may be applied to the best advantage, whereby a considerable gain in speed may be obtained and the machine may be driven zo with the expenditure of less power than in ordinary bicycles.

For a better comprehension of my invention attention is directed to the accompanying drawings, forming a part of this speciz5 cation, and in which- Figure 1 is a side elevation of a portion of a safety-bicycle provided with my improved driving-gear; Fig. 2, a sectional view thereof ou the line a; of Fig. 1; Fig. 3, an enlarged 3o sectional view of the crank-shaft, showin gthe bearings for the same; Fig. 4, an enlarged side elevation of one of the sliding blocks at each end of the crank-shaft, illustrating the preferred construction of said sliding blocks;

Fig. 5, an edge view of the same; Fig. 6, asection on the line 1/'y of Fig.4; Fig. 7, a section on the line .e .e ot' liig. 4; and Fig. 8, an elevation of the preferred form ot crank with the .pedal removed. i

4c In all of the above views corresponding Y parts are designated by the same characters of reference.

1 represents the ordinary crank-hanger of a safety-bicycle, which generally consists ot' 4 5 a heavy steel tube to which the various frames are welded.

2 is an eccentric, made preferablyof steel and of proper size at each side of the machine.

` Each eccentric is provided with an integral 5o sleeve 3, which ts tightly within the crankhanger l, being held in place by a set-screw 4.- or in any other suitable way. By means of this construction the eccentrics are held very firmly and rigidly in place, so that said eccentrics will be always kept in their proper planes. In order that these eccentrics may be as light as possible, I cut them away at 5, so as to leave a main portion through which the crank passes and an outer web for receiving the eccentricstrap. The periphery of each ec- 6o centric is provided, preferably, with a curved groove therein, as shown, for receiving balls 6.

7 is the eccentric -strap which encircles each eccentric, being preferably made in two parts, as shown, and provided with lugs or ears 8 8, which are secured together by screws, rivets, or bolts 9, so that the eccentric-strap maybe removed when necessary. Each eccentric-strap is provided on its inner face with a groove within which the balls 6 work. By 7o means of the construction described the eccentric-straps 7 will be so mounted with respect to the eccentrics 2 as to revolve with very little friction, and at the same time a very compact and strong construction is obtained.

10 is a depending integral lug or ear on each eccentric-,strap 7, carrying a pin or bearing-piece l1, havinga contracted portion 12 for receiving the rear end of the crank, as shown, 8o and with a screw-threaded outer end 13.

Each eccentric 2 is provided with av reinforced portion or hub 14, and onthe inside of this reinforced portion is an annular recess 15, upon which the balls 16 travel. 85

17 is the main driving-shaft or crankshaft of the machine, which works within the eccentrics 2 and crank-hanger 1, as shown. Each end of this crank-shaft 18 is provided with a square outer part 17 for receiving the sliding 9c blocks, which will be presently described.

19 is the main sprocket-wheel of the machine, which maybe made of largerdiameter than is usual, owing to the increased power which I obtain by reason of my improved 9 5 construction. In practice I have found that this sprocket-wheel may be conveniently made of adiameter of between nine and ten inches. The hub 2O of this sprocket-wheel is keyed to the shaft 17 near one end thereof 10o by means of a key 21; but any other means for rigidly securing this sprocket-wheel in position on the crank-shaft may be employed.

The hub 20 is provided with a conical projection 22, which works within the annular recess 15 ot' the eccentric 2 and is supported by the balls 16. Each eccentric 2 is provided with an annular groove or recess 23 outside of the bearing, and working in contact with the inner edge or rim of this recess is a lip or ridge 24, formed on the hub 2O of the sprocket-wheel 19. In practice an annular ring, of felt or othersuitable packing, is placed within the groove or recess 23 and may be saturated with oil or other suitable lubricant, By making use of this construction dust and dirt are prevented from getting into the bearings andthe parts will be automatically oiled.

Ou the other side of the machine the crankshaft 17 is screw-threaded at 25, and engaging with this thread is a cup 26, provided with a conical projection 27, corresponding to the projection 22 ofthe hub 20, and which is supported by the balls 16.

281s a small collar, which also engages with the thread 25, and which is adapted to be screwed up against the cup 26, so as to prevent the latter from becoming loosened. The collar 23 may be locked in position by means of a set-screw 29.

It will be seen that by adjusting the cup 26 in either direction the crankshaft 17 will be moved laterally, which will move the bearingcone 22 toward or away from the balls 16 at that side of the machine, and the bearing-cone 27 at the other side of the machine will be correspondingly moved with relation to the other balls lb'. In this way the proper adjustment of the ball-bearings at both sides of the machine can be simultaneously effected by operating a single adjusting-cup at one side only of the machine.

3() 30 represent the cranks of the bicycle provided with ordinary pedals 3l thereon.

'lhe rear end of each crank is mounted on the contracted portion 12 of the pin l1 on the corresponding side of the machine, being held in position by a nut 32 and washer 33. Each crank is provided with a rectangular slot 34 therein, which may be cast or otherwise formed in any suitable way.

In Fig. 1 l show one form of crank which can be used, if desired, and in Fig. 8 I have illustrated the preferred construction of crank. Itis to be understood, however, that either form of crank may be employed. The crank shown in Fig. lis provided with a main portion 35, formed with two parallel arms 36, so as to resemble a tuning-fork in shape.

37 is a metal block secured between the ends ofthe arms 36 by means of bolts or rivets 38. By making use of this form of crank the slot 34 can be very easily made, and the block 37 may be made of very hard metal, so as to resist wear. Moreover, should the blocks 37 become worn they may be removed and new blocks substituted. In the preferred form of crank shown in Fig. 8 it is made in a single piece and may be conveniently cast or forged or stamped, cut, or otherwise formed out ot' a steel plate of the desired thickness.

Working within each slot 34 is a sliding block 39, keyed or otherwise rigidly secured to each end of the, crank-shaft 17.

Although a solid block may be employed, I prefer to make use either of the construction shown in Figs. 1 and 2 or the preferred construction illustrated in Figs. 4, 5, 6, and 7.

Referring to Figs. 1 and 2, 40 40 are two steel plates or flanges, generally rectangular in form, arranged on each side of the pedal and slightly greater in width than the slots 34. These plates or danges 40 are connected together by a block 4l, which works withink the slot 34. rlhe flanges 40 are preferably made integral with the block 41, in which case the crank should be of the construction shown in Figs. l and 2, wherein the block 37 may be removed to allow the sliding block to beintroduced into the slot 34. Each plate 40 is provided with a rectangular hole therein, which fits over the rectangular end 1S of the crank-shaft 17. Mounted between the plates 40 are rollers 42, which take up the wear of the parts.

In Figs. 4. 5, 6, and 7 I show the preferred form of sliding block, in which any wear ot' the rollers 42 or crank can be quickly and accurately adjusted. This'sliding block is made of two parts 43 and 44, the former being provided with flanges 45, which work against one of the sides of the crank. The main portion of the part 43 is formed with a rectangular recess 46, in which tits a correspondinglyshaped extension 47 on the part 44.

48 4S are Wedges fitting between the two parts 43 and 44, arranged on each side of the extension 47. These Wedges are operated by means of screws 49, passing through the part 43, and by means of which the parts may be separated more or less, as may be desired. The part 44 at the edge thereof is provided with a iiange 50, which corresponds to the flange 45 of the part 43. Rollers 5l 5l are carried in the part 43 and work against one side of the slot 34 of the cranks, and other and similar rollers 52 52 are mounted in the part 44 and work against the other side of the slot 34, the said rollers 5l and 52 being kept in their proper positions by their contact with the sides of the slot 34.

The part 44 of each sliding block is provided with a rectangular opening 53 for :eceiving the end of the crank-shaft, and another opening 54 (see Fig. '7) is formed in the part 43, said latter opening being slightly elongated to allow for the relative movement of the parts.

In placing the improved sliding block in the slot 34 of each crank the parts 43 and 44 are separated and the part 43 and rollers 5l are inserted in place in said slot'. The part 44,

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carrying the rollers 52, is now fitted over the part 43 and the wedges 48 are iinally inserted.

, are separated, so as to work closely within the slot In this way any wear of the parts can be quickly and accurately compensated for.

The operation of my improved device is as follows: The cranks being operated in the usual way will rotate the crank-shaft 17 by the torsional pressure imposed upon the blocks 39, and as the sprocket-wheel 19 is keyed to said shaft the driving-wheel of the bicycle will be operated in the usual way. The rear end of each crank, being connected by means of the pin 11 to the corresponding eccentric-strap 7, will carry said eccentricstrap around the corresponding eccentric 2, and this movement will cause the cranks 30 to reciprocate with respect to the crank-shaft 17, whereby the distance between the pedal 31 and the crank-shaft 17 on the downstroke will be greater than on the upstroke and the resulting power applied to the machine will be correspondingly increased.

By varying the size and position of the eccentrics 2 the amplitude of reciprocation of the cranks 30 will be correspondingly changed. From an inspection of the drawings, taken in connection with the above description, the applicability of my present improvement to existing types of safety-bicycles will be immediately apparent, it being obvious that the only change necessary in such bicyles consists in the removal of the cranks, sprocket-wheel, bearings, and crankshaft therefrom and the provision of two openings or passages in the crank'hanger 1 for the reception of the set-screws 4.

In the improved device all moving parts are provided with ball-bearings or rollingbearings, so that friction will be reduced toa minimum, and all the moving parts are effectively protected against dust and dirt, so that they cannot become clogged in use.

Having now described my invention, what 1 claim as new, and desire to secure by Letters Patent, is as follows:

1. In a driving gear for safety bicycles, the combination of the crank hanger 1 of the bicycle, an eccentric 2 at each side thereof, having an integral sleeve 3 rigidly secured Within said crank hanger, an eccentric strap or band 7 mounted on each eccentric, an annular recess 15 in each eccentric, a crank shaft 17 mounted in said crank hanger, a sprocket wheel 19, having a hub 20 which is keyed to said crank shaft, a conical projection 22 eX- tending from said hub 2O into the recess l5 of the adjacent eccentric, balls 16 between said projection 22 and recess, a cup 26 screwed on the other end of the crank shaft, a conical projection 27 extending from said cup into the recess of the other eccentric, balls 16 between said projection 27 and recess; a sliding block 39 rigidly secured to each end of the crank shaft, and a crank 30 connected at the rear end with the corresponding eccentric strap and provided with a slot 34 therein, for the reception of said sliding block, substantially as set forth.

2. In a driving gear for safety bicycles, the combination of the crank hanger 1 of the bicycle; an eccentric 2 rigidly secured at each side thereof; an eccentric strap or band 7 mounted on each eccentric; a bearing pin 11 carried by each eccentric strap; a crank shaft 17 mounted in said crank hanger and carrying a sprocket wheel 19; a crank 30 mounted at its rear end on each of the bearing pins 11, a slot 34 in each crank through which extends one end of the crank shaft 17, anda sliding block secured to each end of the crank shaft and working in the slot 34 of each crank, said sliding block consisting of two sections 43 and 44, the section 44 being provided with an extension 47 in which the ends of the crank shaft are keyed, and the section 43 being recessed to receive such extension, whereby the parts will beinterlocked but will be movable with respect to each other, so as to take up wear with the inner faces of the slot 34, substantially as set forth.

3. In a driving gear for safety bicycles,the combination of the crank hanger 1 of the bicycle; an eccentric 2 rigidly secured at each Side thereof 5 an eccentric strap or band 7 mounted on each eccentric; a bearing pin 11 carried by each eccentric strap; a crank shaft 17 mounted in said crank hanger and carrying a sprocket wheel 19; a crank 30 mounted at its rear end on each of the bearing pins 11 a slot 34 in each crank through which eX- tends one end of the crank shaft 17, a sliding block secured to each end of the crank shaft and working in the slot 34 of each crank, said sliding block consisting of two sections 43 and 44, the section 44 being provided with an extension 47 in which the ends of the crank shaft are keyed, and the section 43 being recessed to receive such extension, whereby the parts will be interlccked but will be movable with respect to each other, so as to take up wear with the inner faces of the slot 34; wedges 48, 48 mounted between the two sections; and adjusting screws 49 engaging with the section 44, for adjusting said wedges,substantially as set forth.

In testimony whereof l afiix my signature in presence of two witnesses.

JOHN RAU.

W itnesses:

ROSE B. ROLF, MICHAEL Manso.

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